Fluidborne projectors for delivery of sound to fluid filled piping systems is already well known in the art as disclosed for example in U.S. Pat. No. 6,320,821 to Goldring et al. Such fluidborne sound projectors make use of an electro-mechanical shaker as a source of sound applied to one axial end of a piston within a conduit chamber through a piston rod connected to the piston to excite fluid within a piping system to which the conduit is connected. A series of pressure equalization tanks were heretofore associated with such a fluidborne sound projector to maintain the piston in a neutral position within the conduit chamber by means of pressurized air supplied thereto through top openings in the chamber conduit. Reliance on such use of pressurized air tanks and the expenses associated therewith resulted in relatively high costs. It is therefore an important object of the present invention to reduce costs by eliminating use of such pressure equalization tanks and the complexities associated therewith.